Reducing instrument for spinal surgery

Abstract

An instrument is provided for use in orthopedic surgery for reduction of a connecting member such as a spinal rod toward an implant such as a bone screw. An embodiment of the instrument includes handle portions that are pivotable relative to each other and biased apart, and arm portions pivotable relative to each other and to the handle portions. Distal portions of the arm portions, which may be offset from the arm portions, provide structure for engaging a connecting member and an implant. Squeezing the handle portions force the distal portions of the arm portions together, forcing together the connecting member and the implant. A toothed bar and pawl may be provided to retain the instrument in a squeezed state.

1. A rod reducing apparatus comprising:
 first and second handle elements each having a proximal portion and a distal end, said handle elements being pivotally connected to each other adjacent said distal ends of said handle elements; 
 at least one spring connected to at least one of said handle elements and between said handle elements, whereby said handle elements are biased apart; and 
 first and second arm elements each having a proximal end and a distal end, said arm elements being pivotally connected to each other between said ends, said proximal end of said first arm element being pivotally connected to said distal end of said first handle element, and said proximal end of said second arm element being pivotally connected to said distal end of said second handle element, whereby bringing together said first and second handle elements brings together said distal ends of said arm elements; 
 said distal end of said first arm element having at least one extension portion having a proximal end and a distal end, wherein at least one engagement member is positioned at said distal end of said at least one extension portion and configured to contact an orthopedic bone anchor having two spaced apart branches defining a channel therebetween sized to receive a spinal rod; 
 said distal end of said second arm element having a substantially U-shaped portion, said U-shaped portion having two extension portions substantially parallel to said second arm element and a pair of cross-pieces joining said extension portions with a gap formed between said pair of cross-pieces, said U-shaped portion connecting to the remainder of said second arm element adjacent one or both of one of said cross-pieces and one of said extension portions, said extension portions having respective distal ends, said distal ends of said extension portions of said second arm element each including a substantially part-cylindrical hollow, said hollows being substantially coaxial and having a radius equal to or larger than the radius of a the spinal rod; 
 wherein said at least one engagement member defined by said at least one extension portion of said first arm element is pivotally engaged with said orthopedic bone anchor at a pivot engagement location defining a pivot axis, and wherein said first arm element pivots with respect to said orthopedic implant at said pivot engagement location about said pivot axis, and said first and second arm elements are operable to force the spinal rod and the orthopedic bone anchor together, and wherein one of the branches of the orthopedic bone anchor is generally aligned with said gap between said cross-pieces of said second arm element when said spinal rod is positioned within said channel. 
 
   
   
     2. The apparatus of  claim 1 , wherein one of said cross-pieces is more proximal to said handle portions and one of said cross-pieces is more distal from said handle portions, and said more distal cross-piece includes a tab portion. 
   
   
     3. The apparatus of  claim 2 , wherein said tab portion is at least partially curved. 
   
   
     4. The apparatus of  claim 1 , wherein said U-shaped portion of said second arm element is angled toward said first arm element. 
   
   
     5. The apparatus of  claim 4 , wherein said second arm element has a longitudinal axis, and the angle between said axis and said U-shaped portion of said second arm element is about 160 degrees. 
   
   
     6. The apparatus of  claim 1 , wherein said distal end of said first arm element has two extension portions positioned substantially parallel to said first arm element and a cross-piece joining said extension portions, wherein said at least one engagement member includes two protrusions, each distal end of said two extension portions including one of said protrusions, said protrusions substantially facing each other. 
   
   
     7. The apparatus of  claim 1 , wherein said at least one engagement member is a single cylindrical portion positioned at said distal end of said at least one extension portion of said first arm element. 
   
   
     8. The apparatus of  claim 1 , wherein said at least one engagement member is a piece defining a hollow positioned at said distal end of said at least one extension portion of said first arm element. 
   
   
     9. The apparatus of  claim 8 , wherein said anchor includes a protrusion, said hollow being configured to receive at least a portion of said protrusion. 
   
   
     10. The apparatus of  claim 1 , wherein said first and second arm elements each include a curved portion between said distal and proximal ends of said arm elements, wherein said curved portions open in a direction from one arm element towards the other arm element. 
   
   
     11. The apparatus of  claim 1 , wherein said part-cylindrical hollows each include a circumference of about one-fourth the circumference of a circle. 
   
   
     12. A rod reducing apparatus comprising:
 first and second handle elements each having a proximal portion and a distal end, said handle elements being pivotally connected to each other adjacent said distal ends of said handle elements; 
 at least one spring connected to at least one of said handle elements and between said handle elements, whereby said handle elements are biased apart; and 
 first and second arm elements each having a proximal end and a distal end, said arm elements being pivotally connected to each other between said ends, said proximal end of said first arm element being pivotally connected to said distal end of said first handle element, and said proximal end of said second arm element being pivotally connected to said distal end of said second handle element, whereby bringing together said first and second handle elements brings together said distal ends of said arm elements; 
 said distal end of said first arm element having at least one extension portion having a proximal end and a distal end, wherein a cylindrical portion is positioned proximal said distal end of said at least one extension portion and configured to contact an anchor, said cylindrical portion being substantially linear and arranged along a pivot axis positioned substantially perpendicular to said at least one extension portion, said cylindrical portion configured to accommodate a corresponding cylindrical-shaped feature of said anchor, said cylindrical portion pivotably engaged with said cylindrical-shaped feature at a pivot engagement location defining said pivot axis, wherein said first arm element pivots with respect to said anchor at said pivot engagement location about said pivot axis; 
 said distal end of said second arm element having a substantially U-shaped portion, said U-shaped portion having two extension portions substantially parallel to said second arm element and a pair of cross-pieces joining said extension portions, said U-shaped portion connecting to the remainder of said second arm element adjacent one or both of one of said cross-pieces and one of said extension portions, said extension portions having respective distal ends, said distal ends of said extension portions each including a substantially part-cylindrical hollow, said hollows being substantially coaxial and having a radius equal to or larger than the radius of a spinal rod. 
 
   
   
     13. The apparatus of  claim 12 , wherein said first and second arm elements each include a curved portion between said distal and proximal ends of said arm elements, wherein said curved portions are positioned in a first plane, both of said handle elements being positioned in a second plane, wherein said first and second planes are parallel. 
   
   
     14. The apparatus of  claim 12 , wherein said part-cylindrical hollows each include a circumference of about one-fourth the circumference of a circle. 
   
   
     15. The apparatus of  claim 14 , wherein each of said distal ends of said extension portions of said second arm element includes a straight segment adjacent said part-cylindrical hollow. 
   
   
     16. The apparatus of  claim 12 , wherein said extension portion of said first arm element includes a bend of about 90 degrees, said cylindrical portion being offset from said extension portion in a direction toward said second arm element. 
   
   
     17. The apparatus of  claim 12 , wherein said distal end of said first arm element includes two extension portions substantially parallel to said first arm element and a first cross-piece joining said extensions portions at said proximal ends, wherein said cylindrical portion is a second cross-piece joining said distal ends of said extension portions. 
   
   
     18. The apparatus of  claim 17 , wherein the apparatus is used in conjunction with an orthopedic bone anchor having two spaced branches, and said first cross-piece and said cylindrical portion are separated by a gap sufficient to admit one of said branches. 
   
   
     19. A rod reduction apparatus comprising:
 a first arm portion adapted to connect to an orthopedic rod, said arm portion including two extensions and two cross-pieces substantially perpendicular to said extensions, said extensions and said cross-pieces forming a gap, said extensions each having a hollow for accommodating the orthopedic rod; and 
 a second arm portion adjacent said first arm portion, said second arm portion being adapted to connect to an orthopedic implant having two spaced apart branches defining a channel therebetween sized to receive the orthopedic rod, said second arm portion including one or more extension portions having distal and proximal ends, wherein a cylindrical portion is positioned proximal said distal ends and configured to contact the orthopedic implant, said cylindrical portion pivotally engaged with said orthopedic implant at a pivot engagement location defining a pivot axis, wherein said first arm element pivots with respect to said orthopedic implant at said pivot engagement location about said pivot axis substantially parallel to an axis of said channel; 
 whereby said arm portions are operable to force the orthopedic rod and the orthopedic implant together. 
 
   
   
     20. The apparatus of  claim 19 , wherein one of said cross-pieces of said first arm portion is adjacent said hollows of said extensions and includes a tab portion that is at least partially curved, said curve being configured approximately the same as said hollows. 
   
   
     21. The apparatus of  claim 19 , wherein said hollows form a substantially quarter-circular section. 
   
   
     22. The apparatus of  claim 19 , wherein said first arm portion includes two extension portions substantially parallel to said first arm portion, wherein said cylindrical portion is a first cross-piece joining said distal ends of said extension portions. 
   
   
     23. The apparatus of  claim 22 , wherein a second cross-piece joins said proximal ends of said extension portions, said second cross-piece and said cylindrical portion defining a gap wide enough to allow a branch of the orthopedic implant to at least partially pass through. 
   
   
     24. The apparatus of  claim 19 , wherein said first arm portion includes one extension portion, said one extension portion including a bend of about 90 degrees so that said cylindrical portion is offset from said extension portion in a direction toward said second arm portion. 
   
   
     25. The apparatus of  claim 19 , wherein said first and second arm portions each include a curved section between the ends of said arm portions, wherein said curved sections open in a direction from one arm portion to the other arm portion. 
   
   
     26. An apparatus for reducing an elongated member to an orthopedic implant having a channel for receiving the elongated member, comprising:
 a first portion adapted to be connected to the implant, said first portion being pivotable with respect to the implant around an axis substantially parallel to an axis of the implant channel when said first portion is connected to the implant; 
 a second portion adapted to contact the rod, said second portion being connected to said first portion so that said portions can be forced generally toward each other, wherein when said second portion contacts the rod, forcing said portions generally toward each other urges the rod generally toward the implant, and pivoting said first portion around the implant urges said rod toward general alignment with the implant channel; 
 wherein when said second portion contacts the rod and the implant is connected to a bone, forcing said portions generally together pushes the rod generally parallel to a bone surface, and pivoting said first portion around the implant pushes the rod generally perpendicular to the bone. 
 
   
   
     27. A rod reduction apparatus comprising:
 a first arm portion adapted to connect to an orthopedic rod, said arm portion including two extensions and two cross-pieces substantially perpendicular to said extensions, said extensions and said cross-pieces forming a gap, said extensions each having a hollow for accommodating the orthopedic rod; and 
 a second arm portion adjacent said first arm portion, said second arm portion being adapted to connect to an orthopedic implant having two spaced apart branches defining a channel therebetween sized to receive the orthopedic rod, said second arm portion including one or more extension portions having distal and proximal ends, wherein a cylindrical portion is positioned proximal said distal ends and configured to contact the orthopedic implant, said cylindrical portion pivotally engaged with said orthopedic implant wherein said first arm element pivots with respect to said orthopedic implant about a pivot axis substantially parallel to an axis of said channel, wherein said cylindrical portion is substantially linear and is positioned substantially perpendicular to said one or more extension portions; 
 whereby said arm portions are operable to force the orthopedic rod and the orthopedic implant together. 
 
   
   
     28. A rod reduction apparatus comprising:
 a first arm portion adapted to connect to an orthopedic rod, said arm portion including two extensions and two cross-pieces substantially perpendicular to said extensions, said extensions and said cross-pieces forming a gap, said extensions each having a hollow for accommodating the orthopedic rod; and 
 a second arm portion adjacent said first arm portion, said second arm portion being adapted to connect to an orthopedic implant having two spaced apart branches defining a channel therebetween sized to receive the orthopedic rod, said second arm portion including one or more extension portions having distal and proximal ends, wherein a cylindrical portion is positioned proximal said distal ends and configured to contact the orthopedic implant, said cylindrical portion pivotally engaged with said orthopedic implant wherein said first arm element pivots with respect to said orthopedic implant about a pivot axis substantially parallel to an axis of said channel, wherein said cylindrical portion is configured to accommodate a corresponding cylindrical-shaped feature of said orthopedic implant, said cylindrical portion pivotally engaged with said cylindrical-shaped feature wherein said second arm portion pivots with respect to said orthopedic implant about said pivot axis; 
 whereby said arm portions are operable to force the orthopedic rod and the orthopedic implant together. 
 
   
   
     29. An apparatus for reducing an elongated member to an orthopedic implant having a channel for receiving the elongated member, comprising:
 a first portion adapted to be connected to the implant, said first portion being pivotable with respect to the implant around an axis substantially parallel to an axis of the implant channel when said first portion is connected to the implant; 
 a second portion adapted to contact the rod, said second portion being connected to said first portion so that said portions can be forced generally toward each other, wherein when said second portion contacts the rod, forcing said portions generally toward each other urges the rod generally toward the implant, and pivoting said first portion around the implant urges said rod toward general alignment with the implant channel; 
 wherein said first portion is pivotally engaged with said implant to provide said pivoting of said first portion around said implant and 
 wherein said first portion includes at least one pivot engagement member arranged along a pivot axis substantially parallel to said axis of said implant channel, said at least one pivot engagement member pivotally engaged with a corresponding portion of said implant at a pivot engagement location defining said pivot axis, and wherein said at least one pivot engagement member pivots with respect to said implant at said pivot engagement location about said pivot axis. 
 
   
   
     30. The apparatus of  claim 29 , wherein said first portion is a part of a first arm, said second portion is a part of a second arm, said arms being hingedly connected, and further comprising a handle portion including one or more handle elements, said handle portion connected to said arms so that activating said handle portion forces said end portions of said arms generally toward each other. 
   
   
     31. The apparatus of  claim 29 , wherein when said second portion contacts the rod and the implant is connected to a bone so that the implant extends in a first direction away from the bone, forcing said portions generally toward each other pushes the rod generally obliquely or perpendicularly with respect to said first direction, and pivoting said first portion around the implant pushes the rod in a direction having at least a component that is parallel to said first direction.